1. Field of the Invention
The present invention relates to a gas adsorbing element and a method of manufacturing the gas adsorbing element. More particularly, the present invention relates to an element for adsorbing an active gas from an inert gas so that only ultra-low concentrations of the active gas remain in the inert gas after processing.
2. Description of the Related Art
In cross-referenced U.S. patent application having Ser. No. 852,291, a method for manufacturing a humidity exchanger element or total heat energy exchanger element is disclosed. The element includes a silicate aerogel having a matrix of inorganic fiber papers. Low density papers of inorganic fibers, such as ceramic fibers, are laminated together in the shape of a humidity exchanger element or total heat energy exchanger element having many small channels. The laminate is impregnated with a water glass solution either before or after the matrix forming process. The laminate is then soaked in a water solution of aluminum salts, magnesium salts or calcium salts to produce silicate hydrogel. This element is then washed with water and dried to obtain the final product.
Japanese patent publication No. 19548/1979 (laid open to the public without examination) discloses a regeneratable dehumidifying rotor. The rotor is made of asbestos papers containing synthesized zeolite. The papers are formed into an element containing numerous small channels. Another regeneratable dehumidifying rotor is made of metal sheets, papers, or non-woven fabric sheets formed into an element having numerous small channels. The sheets or papers carry synthesized zeolite on their surface as a desiccant.
Japanese patent publications Nos. 62598/1985 and 246000/1985 (laid open to public without examination) disclose a method of adhering and combining synthesized zeolite as a desiccant to the surface of the metal or fabric sheets, etc., by using silica gel.
Silica gel used as an adhering and combining agent, as described above, has minimal desiccative properties. Accordingly, the greater the volume of silica gel or other inorganic binders used, the lower the dehumidifying ability per unit weight of the dehumidifying element. When the volume of the binder decreases, the physical strength of the dehumidifying element also decreases and the element cannot be used.
Feed air having a normal temperature and desorbing air having a high temperature pass through the small channel of the element. Adsorbent powder such as silica gel, or synthesized zeolite, on the papers forming the small channels drops off and scatters due to repeated wind pressure and heating and cooling by the feed air and the desorbing air.
Synthesized zeolite does have excellent properties for adsorbing humidity and other active gases from inert gases such as air. This is especially true for synthesized zeolite having small diameter pores adhered to an element matrix. One option is to form paper by mixing synthesized zeolite. However, this is expensive the yield is 50% of less, and the synthesized zeolite on the paper has low adhering properties. Synthesized zeolite also cannot be effectively regenerated. That is, the adsorbed humidity cannot be removed fully from the element without high temperatures being applied. Thus, regeneration of the element is impractical unless temperatures are higher than 140.degree. C.